The incident is being treated as terrorism.

A suspect deliberately drove a car at police outside Buckingham Palace, reached for a four foot sword and shouted “Allahu Akbar” before being incapacitated with CS spray, the Metropolitan Police have said.

Three officers were injured after tackling a man who drove a blue Toyota Prius at a marked police vehicle on Friday night outside the palace.

He was further arrested under the Terrorism Act 2000 and remains in custody at a central London police station.

Two of the officers were taken by ambulance to hospital with minor cuts and discharged a short time later. The third officer did not require hospital treatment.

The Met said the incident is now being treated as terrorism.

Commander Dean Haydon, the head of the Met’s Counter Terrorism Command, said: “I would like to pay tribute to the bravery and professionalism of these officers who quickly brought this incident under control. Their vigilance, courage and the swiftness of their response demonstrates how our officers are protecting the public at this time.

“Officers from the Counter Terrorism Command are now investigating and searches are being carried out in the Luton area today.

“We believe the man was acting alone and we are not looking for other suspects at this stage. While we cannot speculate on what the man was intending to do - this will be determined during the course of the investigation - it is only right that we investigate this as a terrorist incident at this time.

“I would urge anybody who witnessed the incident or has any information or images that may assist the investigation to contact the confidential hotline on 0800 789 321.”

Commander Haydon added: “This is a timely reminder that the threat from terrorism in the UK remains severe. The police, together with the security services, are doing everything we can to protect the public and we already have an enhanced policing plan over the Bank Holiday weekend to keep the public safe.

“We continue to urge the public to be alert but not alarmed and report anything suspicious to police confidentially on the hotline - 0800 789 321. In an emergency always call 999.”